Hollow Regalia, Vol. 4 (light novel) — Gakuto Mikumo

Yahiro and the gang head to Kyoto hoping to figure out how to turn the Japanese populace back into humans. When Galerie Berith's armored train stops in Nagoya, the Chinese Federal Army, the current occupant of the former Nagoya Station, demands that the Galerie surrender Vanagloria's Regalia in exchange for safe passage. By that time, the powerful Relict has fused with Ayaho, and handing over one of Iroha's siblings is the last thing they'd do. Can they protect her, negotiate their way out of the situation, and defend against a herd of Moujuu all at once?